# Define here the models for your spider middleware
#
# See documentation in:
# https://docs.scrapy.org/en/latest/topics/spider-middleware.html

from scrapy import signals
import random
import base64
# from tor01 import get_IP

# from settings import USER_AGENTS
# from settings import PROXIES
# useful for handling different item types with a single interface
from itemadapter import is_item, ItemAdapter


# 随机的User-Agent
class RandomUserAgent(object):
    def process_request(self, request, spider):
        # useragent = random.choice(USER_AGENTS)
        useragent = random.choice(spider.settings.get('USER_AGENTS'))
        request.headers.setdefault("User-Agent", useragent)

# 随机代理
class RandomProxy(object):
    def process_request(self, request, spider):
        # proxy = random.choice(PROXIES)
        proxy = random.choice(spider.settings.get('PROXIES'))
        # proxy = get_IP()
        request.meta['proxy'] = proxy


        # if proxy['user_passwd'] is None:
        #     # 没有代理账户验证的代理使用方式
        #     request.meta['proxy'] = "http://" + proxy['ip_port']
        # else:
        #     # 对账户密码进行base64编码转换
        #     base64_userpasswd = base64.b64encode(proxy['user_passwd'])
        #     # 对应到代理服务器的信令格式里
        #     request.headers['Proxy-Authorization'] = 'Basic ' + base64_userpasswd
        #     request.meta['proxy'] = "http://" + proxy['ip_port']


# class ProxyMiddleware(object):
#     '''
#     设置Proxy
#     '''

#     def __init__(self, ip):
#         self.ip = ip

#     @classmethod
#     def from_crawler(cls, crawler):
#         return cls(ip=crawler.settings.get('ProxyMiddlewareIES'))

#     def process_request(self, request, spider):
#         ip = random.choice(self.ip)
#         request.meta['proxy'] = ip



class MztrSpiderMiddleware:
    # Not all methods need to be defined. If a method is not defined,
    # scrapy acts as if the spider middleware does not modify the
    # passed objects.

    @classmethod
    def from_crawler(cls, crawler):
        # This method is used by Scrapy to create your spiders.
        s = cls()
        crawler.signals.connect(s.spider_opened, signal=signals.spider_opened)
        return s

    def process_spider_input(self, response, spider):
        # Called for each response that goes through the spider
        # middleware and into the spider.

        # Should return None or raise an exception.
        return None

    def process_spider_output(self, response, result, spider):
        # Called with the results returned from the Spider, after
        # it has processed the response.

        # Must return an iterable of Request, or item objects.
        for i in result:
            yield i

    def process_spider_exception(self, response, exception, spider):
        # Called when a spider or process_spider_input() method
        # (from other spider middleware) raises an exception.

        # Should return either None or an iterable of Request or item objects.
        pass

    def process_start_requests(self, start_requests, spider):
        # Called with the start requests of the spider, and works
        # similarly to the process_spider_output() method, except
        # that it doesn’t have a response associated.

        # Must return only requests (not items).
        for r in start_requests:
            yield r

    def spider_opened(self, spider):
        spider.logger.info('Spider opened: %s' % spider.name)


class MztrDownloaderMiddleware:
    # Not all methods need to be defined. If a method is not defined,
    # scrapy acts as if the downloader middleware does not modify the
    # passed objects.

    @classmethod
    def from_crawler(cls, crawler):
        # This method is used by Scrapy to create your spiders.
        s = cls()
        crawler.signals.connect(s.spider_opened, signal=signals.spider_opened)
        return s

    def process_request(self, request, spider):
        # Called for each request that goes through the downloader
        # middleware.

        # Must either:
        # - return None: continue processing this request
        # - or return a Response object
        # - or return a Request object
        # - or raise IgnoreRequest: process_exception() methods of
        #   installed downloader middleware will be called
        return None

    def process_response(self, request, response, spider):
        # Called with the response returned from the downloader.

        # Must either;
        # - return a Response object
        # - return a Request object
        # - or raise IgnoreRequest
        return response

    def process_exception(self, request, exception, spider):
        # Called when a download handler or a process_request()
        # (from other downloader middleware) raises an exception.

        # Must either:
        # - return None: continue processing this exception
        # - return a Response object: stops process_exception() chain
        # - return a Request object: stops process_exception() chain
        pass

    def spider_opened(self, spider):
        spider.logger.info('Spider opened: %s' % spider.name)
